1. Field of the Invention
High blood pressure is a widespread condition which has become, especially in recent years, the object of intensive concern and effort with respect to alleviating the life-threatening effects of its presence. The invention herein concerns a class of 1-substituted spiropiperidine heterocycles which are effective in the central nervous system (CNS) and are useful in treating hypertension.
2. Background of the Invention
It has become clear that at least some of the factors controlling blood pressure reside in the CNS. By altering the state of the receptors for adrenergic compounds through providing compounds suitable for binding at these sites, outcomes such as vasodilation or constriction, heartbeat rate acceleration or slowdown, and heart blood vessel pressure changes can be effected.
The compounds of the present invention have been shown to lower blood pressure. These compounds are spiro[piperidine-oxobenzooxazine]s. The literature describes certain other compounds with superficially similar structures, different from the compounds of this invention. For example, U.S. Pat. No. 4,224,333, issued Sept. 30, 1980 discloses 2-(benzodioxan-2-yl)-2-hydroxyethylpiperidines; substituted with 2H-indol-2-ones at the 4-position of the piperidine ring, as antihypertensives.